This directive can be abused to add unnecessary amounts of logic into your templates. There are only a few appropriate uses of ngInit:

• aliasing special properties of ngRepeat, as seen in the demo below.
• initializing data during development, or for examples, as seen throughout these docs.
• injecting data via server side scripting.

Besides these few cases, you should use Components or Controllers rather than ngInit to initialize values on a scope.

<div ng-init="test1 = ($index | toString)"></div>